Airplane a is flying north with a constant horizontal velocity of 488 km/h. airplane b is flying southwest at the same altitude with a velocity of 567 km/h. from the frame of reference of a, determine the magnitude vr of the apparent or relative velocity of b. also find the magnitude of the apparent velocity vn with which b appears to be moving sideways or normal to its centerline. would the results be different if the two airplanes were flying at different but constant altitudes?

While strolling downtown on a saturday afternoon, you stumble across an old car show. as you are walking along an alley toward a main street, you glimpse a particularly stylish alpha romeo pass by. tall buildings on either side of the alley obscure your view, so you see the car only as it passes between the buildings. thinking back to your physics class, you realize that you can calculate the car's acceleration. you estimate the width of the alleyway between the two buildings to be 6 m. the car was in view for 0.6 s. you also heard the engine rev when the car started from a red light, so you know the alpha romeo started from rest 4 s before you first saw it. find the magnitude of its acceleration.